Gender Differences in Receptivity to Sexual Offers should be a screamingly famous research report. Yet most people don't know about it. Or maybe they can't believe it exists. It exists.

Published in 1989 in the Journal of Psychology and Human Sexuality, this nine-page sizzler tells a simple tale. Five women and four men were sent, one at a time, on to a college campus. Each approached strangers of the opposite sex, and said: "I have been noticing you around campus. I find you to be very attractive." They then invited the strangers to have sex.

This experiment was performed twice, once in 1978, and again in 1982. The results were the same. As the report describes it: "The great majority of men were willing to have a sexual liaison with the women who approached them. Not one woman agreed to a sexual liaison."

The study was conceived and directed by two psychology professors, Elaine Hatfield, of the University of Hawaii at Manoa, and Russell D Clark III, of Florida State University.

It begins with a declaration: "According to cultural stereotypes, men are eager for sexual intercourse; it is women who set limits on such activity." It ends with a declamation: "Regardless of why we secured these data, however, the existence of these pronounced gender differences is interesting."

The paper never does exactly explain why they secured the data, but it does supply a list of 59 earlier published studies that they found useful, interesting, or at least worth listing.

These include four other sex-related reports by Hatfield and three technical reports from the prestigious US Commission on Obscenity and Pornography. Fourteen years later, Hatfield and Clark published a study called Love in the Afternoon, in which they tried to explain why they had done the experiment and what happened as a result. Here is a nutshell version of their explanation:

In the spring of 1978, Russ Clark was teaching a small class in experimental social psychology. Russ dropped a bomb. "Most women," he said, "can get any man to do anything they want. Men have it harder. They have to worry about strategy, timing and tricks."

Not surprisingly, the women in the class were incensed. One woman sent a pencil flying in Russ's direction.

In one of Russ's finer moments, he observed: "We don't have to fight. We don't have to upset one another. It's an empirical question. Let's design a field experiment to see who's right!"

Journal after journal refused to publish their paper, giving harsh comments, of which this one is typical: "The study itself is too weird, trivial and frivolous to be interesting. Who cares what the result is to such a silly question."

But Hatfield and Clark were undaunted. As they explain at the end of the paper Love in the Afternoon: "The trivial, uninteresting and morally suspect research of today often turns out to be the classic study of tomorrow."

· Marc Abrahams is editor of the bimonthly magazine Annals of Improbable Research (www.improbable.com) and organiser of the Ig Nobel Prize